# NTSB ANC24LA027: Piper PA-28-151, N4399X, Marana, AZ, April 19, 2024 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: April 19, 2024, 12:30 local (19:30 UTC) - Place: Marana, AZ - Coordinates: 32.594596, -111.18824 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=32.5946&lon=-111.1882&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Alaska Regional Office - Parties: Lycoming Engines, Federal Aviation Administration - NTSB case key (mKey): 194130 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC24LA027 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/194130/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=194130 - Page: https://openairdocs.org/ntsb/ANC24LA027 ## Probable cause A total loss of engine power due to a failure of the No. 4 cylinder piston boss. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (reciprocating): recip eng cyl section](https://openairdocs.org/ntsb-findings/01058530): Aircraft › Aircraft power plant · Malfunction (probable cause) ## Analysis The flight instructor and student pilot were conducting a cross-country flight when the engine began to run rough and make grinding noises. The engine then stopped producing power, and the propeller would not windmill. The instructor attempted to restart the engine and performed a forced landing to a field, during which the airplane sustained substantial damage to both wings. Postaccident examination of the engine revealed significant wear to the camshaft lobes, as well as evidence of catastrophic failure of the No. 4 piston assembly. The damage appeared to originate from the area of the piston pin and boss; however, the failure features were obliterated during the event, preventing an accurate assessment of its origin. The engine was most recently overhauled about 21 years and 2,190 flight hours before the accident. The manufacturer’s recommended time between overhaul (TBO) interval was 2,200 flight hours or 12 years, whichever occurs first. ## Factual narrative On April 19, 2024, about 1230 mountain standard time, a Piper PA-28 airplane, N4399X, was substantially damaged when it was involved in an accident near Marana, Arizona. The flight instructor and student pilot were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. The flight departed Coolidge Municipal Airport (P08), Coolidge, Arizona, about 1210. The pilot reported that, during cruise flight at about 4,500 ft mean sea level, the engine began to run rough and make grinding noises. The engine stopped producing power and the propeller would not windmill. The flight instructor attempted to restart the engine and performed a forced landing to a field, during which the airplane sustained substantial damage to both wings. Examination of the engine revealed no impact related damage and no evidence of fire. A crack was observed beginning above the No. 3 intake valve tappet casing that propagated through the engine crankcase into the oil sump. The right magneto was detached from its mounting flange. The oil cap was in place and there was no evidence of pre-accident oil leak. Both the engine oil filter media and oil suction screen were coated in shiny metallic particles. Disassembly of the engine revealed catastrophic damage to the No. 4 cylinder and piston assembly, with no significant damage to the remaining cylinders or their associated valvetrain components. The No. 4 cylinder connecting rod was bent 45° at the piston pin end and the piston pin had detached and become embedded in the lower section of the crankcase. Even with this damage, all four connecting rods remained connected to the crankshaft and could be moved smoothly around the crankshaft journal. None of the internal components exhibited evidence of heat distress. The camshaft lobes were worn such that between 10% and 50% of the contact face material had worn away. Metal burrs were present on the edges of the cam lobe remnants, and the associated tappet heads were either shattered or exhibited spalling and cupping deformation to their cam lobe contact faces. The No. 4 piston and pin, along with associated fragments, were examined by a specialist in the NTSB Materials Laboratory. The skirt on the piston underside exhibited the most damage. Approximately half of the skirt material was missing, with the demarcation of fracture located along the bore containing the pin. The lower third of the fracture surfaces of the piston exhibited discernible fracture features, while the rest exhibited reflective lusters with erratic streaks consistent with post-fracture smearing damage from impact or rubbing against adjacent parts. In addition, circular impact witness marks were present on the interior surface of the piston remnant. No pre-existing or progressive cracking features were found on the pin or remnants of the piston. Lycoming Engine Service Instruction No. 1009BE stated that the time between overhaul (TBO) for the O-360 engine was 2,200hours of operation or 12 years (whichever occurred first) and that an engine’s published TBO does not mean that every engine will operate the number of hours or years listed without requiring component replacement and/or unscheduled maintenance events. Noncompliance with instructions for continued airworthiness, operational and/or environmental factors may necessitate repair or replacement of the engine, engine components and accessories earlier than the published TBO. According to the maintenance records, the engine was overhauled by the manufacturer on March 5, 2003. The airplane’s most recent 100-hour inspection was completed on April 9, 2024. At the time of the inspection, the engine had accrued approximately 2,189.9 hours of operation since the overhaul in 2003. There was no record in the maintenance logbooks of engine oil analysis having been performed. ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute: Loss of engine power (total)](https://openairdocs.org/ntsb-events/341) (defining event) - [Emergency descent: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440) ## Aircraft - Registration: [N4399X](https://openairdocs.org/aircraft/N4399X), registered now, S/N 28-7615006, built 1975 (OpenAirDocs) - Reported make and model: PIPER PA-28-151 - Registry model: [Piper PA-28-151](https://openairdocs.org/model/piper-pa-28-151) (registry code 7102805) (OpenAirDocs) - Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 28-7615006 - Year built: 1975 - Airframe hours: 7213 - Engines: Lycoming O-360-A4M 180 horsepower reciprocating - Damage: Substantial damage - Flight: Instructional, Part 91 - Registered owner: Venture West LLC - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, April 9, 2024, 60.4 hours before - Departed: P08, Coolidge, AZ - Destination: KAVQ, Marana, AZ - Airport: P08, Coolidge Municipal - Equipment: ADS-B, Stall warning system, Electronic primary flight display ## Flight crew As NTSB recorded them. NTSB leaves out names. - Flight instructor; age 36; injuries: none; flight instructor; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review December 18, 2023; seat: right; restraint: 3-point; flight hours: 367.4 total, 77.1 in this make and model, 267.8 as pilot in command - Student pilot; age 36; injuries: none; student; medical: class 1, without waivers/limitations; seat: left; restraint: 3-point; flight hours: 27.9 total, 19.6 in this make and model, 27.9 in the last 90 days, 8.7 in the last 30 days, 1.1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 88 °F - Altimeter: 29.88 inHg - Observed at: P08, 13.5 nm away - METAR: KMZJ 192035Z AUTO 24009G15KT 220V280 10SM -RA CLR 33/M08 A2984 RMK AO2 ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20240419006069A](https://openairdocs.org/incident/20240419006069A), Apr 19, 2024: Piper PA-28-151, Marana, AZ, Substantial damage. Pilot stated that he and his student departed falcon field airport (kffz), mesa AZ. At approximately 11:30AM local time (lt) for a VFR cross-country dual… ## Docket (7 files) The files NTSB released with the investigation on April 1, 2025, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=194130. 22.3 MB in all. - Materials laboratory factual report (item 1, PDF, 22 pages, 6.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18439103&FileExtension=pdf&FileName=24-055%20-%20Materials%20Lab%20Factual%20Report%20(ANC24LA027)-Rel.pdf - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 2, PDF, 9 pages, 6.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17079254&FileExtension=pdf&FileName=ANC24LA027%206120_Redacted-Rel.pdf - Engine exam (item 3, PDF, 8 pages, 1.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17458645&FileExtension=pdf&FileName=Engine%20Examination%20ANC24LA027-Rel.pdf - Maintenance records (item 4, PDF, 37 pages, 5.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18467361&FileExtension=pdf&FileName=N4399X%20Engine%20Logs_Redacted-Rel.pdf - Lycoming service instruction tbo (item 5, PDF, 8 pages, 805 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18466610&FileExtension=pdf&FileName=Lycoming%20Service%20Instruction%20Ltr%20TBO-Rel.pdf - Certification of party representative (Lycoming) (item 6, PDF, 14 pages, 209 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=18467470&FileExtension=pdf&FileName=NTSB%20party%20form_Lycoming-ANC24LA027_Redacted-Rel.pdf - Photos (item 7, PDF, 4 pages, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17701711&FileExtension=pdf&FileName=ANC24LA027%20Investigative%20Photographs-Rel.pdf From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.